Member Since: 10 May 2016
Location: Scotland
Posts: 3
Problem with rev’s fluctuating
Hi, hope you can help.
I have a discovery 3 HSE 2008 with 126,000 miles on the clock. Recently it has developed a problem where between 1500 and 1800rpm the revcounter fluctuates up and down and it makes a pulsing droning sound in time with the fluctuations. If i take my foot of the accelerator it stops, if I accelerate and push the rev’s over 1800rpm it stops. The car is functioning perfectly in every way with no errors being flagged and all special functions working fine. It accelerates well and on the motor way is quiet and smooth with plenty of power.
I had the car serviced and MOT’d a week ago and was also advised to get a full gearbox flush at a landrover specialist, which i believe also flushes the filter and the torque converter. I have had this done and on driving the car it has made no difference at all. I have now been advised that perhaps I should have the filter replaced, which will be another £350, and am reluctant to just to start randomly spending money in the hope it makes a difference. Should I just go ahead with the filter change or do we think this could be a more significant problem? Don’t mind spending the money as long as it gets the car fixed.
4th Feb 2018 7:55 pm
Gareth Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26701
Your torque converter is knackered. No point in changing anything else. Plenty of info on here, but it looks like your gearbox flush was just too late to save the TC.
4th Feb 2018 9:53 pm
character
Member Since: 01 Jan 2008
Location: wiltshire
Posts: 5779
torque converter.....having triggers done this week, ZF acredited specialist in Peterborough
btw yes you can spend lots of dosh having it "double flushed" by LR, or stick Dr Tranny shudder fix, but if torque converters going, its only going one way
Tell yer what, seems we need to do a group by on these torque converters with ZF directly !!
5th Feb 2018 12:32 am
CloudbaseJim
Member Since: 20 Dec 2017
Location: Cumbria
Posts: 79
Dr tranny fixed it for me. Worth trying for £10
7th Feb 2018 7:41 pm
SteveS
Member Since: 10 May 2016
Location: Scotland
Posts: 3
Amazed
Well I have to say I am genuinely amazed. Added Dr Tranny via the oil cooler and it has transformed the car. No rev fluctuations, no juddering and very, very smooth power delivery. I do know this is only postponing the inevitable but as this cost £24 and my local landrover independant was quoting me over £1,000 to replace the torque converter i will live with this fix for the time being. I paid £350 for a mega flush which had no effect so the fact that this has made such a difference is surprising, surely this should be the recommended action when a car gets to a certain age.
Thanks for the advice, it has saved me a fortune
17th Feb 2018 5:13 pm
CrazyHorse605
Member Since: 28 Nov 2016
Location: Bristol-Bath
Posts: 10
There seems to be a lot of debate on this recurring topic.
Mine has the issue and after reading I have been flushing it then running it a bit to clean the good oil fully through all the parts (i.e. all gears) then flush again.
I looked quickly at the design and access to it all and unless the gearbox is run through all gears I struggle to see how a flush would work long term. There are parts that unless the car is driven wont see much new oil.
I may try running it through much like an oil flush but just driver it for a few minutes to give it a quick chance (more to read to decide on this).
After the first 2 flushes I have done to date each time the gearbox seems notably better. Although I do not know the full history of the car I can see that the oil in the auto box has been changed at least a few times - the lower coer is missing, the filler bolt had no washer and the bottom drain plug had a minor leak.
All easy fixes and I put the metal sump and filter on it.
Next is probably doing the flush with the stuff above then replacing it with the final fluid.
Having had an rx8 auto which had a failed torque converter (apparently) then the gearbox replaced recently... each time drove it from London to Bristol fine either within 20 minutes to a few days it then stopped running, lurched much as described on the disco here.
After the new gearbox I got to within 5 minutes of home and the car appeared to seize and wouldn't turn to start - like before. Found the a.c. pump was seized and the pulley red hot. Cut the belt as that all that was on it now its like a different car.
Plus 4 friends with RRS D3 and D4 all have the same issue with the rpm surging. So I am reluctant to say they all suddenly need new gearboxes and torque converters until the obvious and less obvious are ruled out.
I'd like to know if anyone has tried the flushing fluid - is that what they use on a power/mega flush as it seems cheaper and will do a better job by description.
If not perhaps I will and report back..... All comments welcome!
Dr Tranny simply increases the viscosity of the oil making it easier for the clutches to grab, the new oil being the correct viscosity will have not held the clutches in place and hence the fluctuation as they grabbed then slipped repeatedly. The increased viscosity cures this, however it also makes all the components work harder, thus shortening their service life.
Ultimately you need a TC, in time this could be a gearbox rebuild.
I've been there with my old D3, flushed, added Dr T, got about 10k before it went again as it will gradually degrade, I then bit the bullet and has a TC fitted
IID Pro MV License - D3, D4 & RRS - Enabling, Updates, D4 & RRS Timed / Remote Climate, D4 Bluetooth fitting
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D4 & RRS style D3 grilles made to order
18th Feb 2018 10:11 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13635
hi
ref that flushing fluid
hope u don’t mind me saying but saw this statement at the bottom of the page concerning this fluid
“ Please note this fluid is ready mixed for use out of the bottle. This product is not a concentrate and is designed to be used where Dexron 2 or Dexron 3 fluids are specified. “
have read etc that any type of dexron mustn’t be used in the 6hp gearboxes
18th Feb 2018 10:13 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13635
beanie wrote:
Dr Tranny simply increases the viscosity of the oil making it easier for the clutches to grab, the new oil being the correct viscosity will have not held the clutches in place and hence the fluctuation as they grabbed then slipped repeatedly. The increased viscosity cures this, however it also makes all the components work harder, thus shortening their service life.
Ultimately you need a TC, in time this could be a gearbox rebuild.
I've been there with my old D3, flushed, added Dr T, got about 10k before it went again as it will gradually degrade, I then bit the bullet and has a TC fitted
Start saving
apologises , hope u didn’t mind me putting the post in after urs ref the dexron ,
IID Pro MV License - D3, D4 & RRS - Enabling, Updates, D4 & RRS Timed / Remote Climate, D4 Bluetooth fitting
PM me for details
Owner of the original "Beanie" grille
D4 & RRS style D3 grilles made to order
18th Feb 2018 11:39 pm
CrazyHorse605
Member Since: 28 Nov 2016
Location: Bristol-Bath
Posts: 10
Hi beanie,
Did you just have the torque converter changed out or a whole gearbox rebuild at the same time?
Are there any parts that dhould be replaced/upgraded while its out and being worked on?
Thanks!
18th Feb 2018 11:44 pm
CrazyHorse605
Member Since: 28 Nov 2016
Location: Bristol-Bath
Posts: 10
beanie wrote:
for Bristol Trans
Hi beanie,
Did you just have the torque converter changed out or a whole gearbox rebuild at the same time?
Are there any parts that dhould be replaced/upgraded while its out and being worked on?
Thanks!
18th Feb 2018 11:45 pm
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10363
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